Aerodynamic Improvement of a Transonic Fan Outlet Guide Vane Using 3D Design Optimization

2011 ◽  
Author(s):  
Giles Endicott ◽  
Toyotaka Sonoda ◽  
Markus Olhofer ◽  
Toshiyuki Arima
Keyword(s):  
Cfd Simulation ◽  
Experimental Testing ◽  
Guide Vane ◽  
Numerical Technique ◽  
Boundary Layer Separation ◽  
Operating Conditions ◽  
Free Form ◽  
Optimized Design ◽  
3D Design ◽  
Transonic Fan

In this paper we follow the process of rapid design improvement for the fan outlet guide vane for a turbofan powering a very light jet. The small size of such engines leads to a low Reynolds number, resulting in flow-fields prone to boundary layer separation, causing significant losses in efficiency. This paper studies experimental testing in a scale rig, and numerical simulation using CFD, leading to the comparison of the two datasets and hence assessment of the numerical technique. The mesh employed by the CFD simulation was modified using Free Form Deformation to create different geometric designs, and hence an optimization scheme was subsequently utilized to find the deformation of 28 variables which maximized aerodynamic performance. The final optimized design displayed a novel oscillatory casing profile, while the blade shape had increased camber relative to the baseline. The improvement in pressure loss was approximately 20% across the range of operating conditions studied.

A Novel Transonic Fan Swept Outlet Guide Vane Using 3D Design Optimization

2014 ◽  
Author(s):  
Toyotaka Sonoda ◽  
Giles Endicott ◽  
Toshiyuki Arima ◽  
Markus Olhofer
Keyword(s):  
Design Optimization ◽  
Guide Vane ◽  
Suction Side ◽  
Optimization Method ◽  
Optimized Design ◽  
Loss Reduction ◽  
3D Design ◽  
Blade Thickness ◽  
Transonic Fan ◽  
Blade Geometry

In our previous work on a transonic fan swept outlet guide vane (OGV) for a small turbofan engine (GT2011-46363), we showed a novel oscillatory casing profile that leads to approximately 20% loss reduction, using a numerical design optimization method. In this paper we analyze the resulting geometry of an optimization based on a blade representation which is able to realize significantly larger surface modifications. The final optimized design displays a novel blade geometry that has its maximum blade thickness at around 80% blade chord (located between the blade’s mid-chord and trailing edge) especially in the mid-span region. The flow physics explaining why this blade geometry without the oscillatory casing profile has the same loss reduction level of more than 20% at the peak efficiency point are discussed, focusing on the secondary flow and span-wise static pressure gradient on the blade suction side.

scholarly journals The Influence of Bulb Position on Hydraulic Performance of Submersible Tubular Pump Device

2021 ◽  
Vol 9 (8) ◽  
pp. 831
Author(s):  
Zhuangzhuang Sun ◽  
Jie Yu ◽  
Fangping Tang
Keyword(s):  
Entropy Production ◽  
Large Scale ◽  
Experimental Testing ◽  
Guide Vane ◽  
Outer Wall ◽  
Hydraulic Performance ◽  
Hydraulic Loss ◽  
Optimized Design ◽  
Outlet Channel ◽  
Wall Area

In order to study the influence of the position of the bulb on the hydraulic performance of asubmersible tubular pump device, based on a large-scale pumping station, two schemes—involving a front-mounted bulb and a rear-mounted bulb, respectively—were designed. The front-mounted scheme uses the GL-2008-03 hydraulic model and its conventional guide vane, while the rearmounted scheme uses the optimized design of a diffuser vane. The method of combining numerical simulation and experimental testing was used to analyze the differences between the external and internal characteristics of the two schemes. The results show that, under the condition of reasonable diffusion guide vane design, the efficiency under the rear-mounted scheme is higher than that under the front-mounted scheme, where the highest efficiency difference is about 1%. Although the frontmounted bulb scheme reduces the hydraulic loss of the bulb section, the placement of the bulb on the water inlet side reduces the flow conditions of the impeller. Affected by the circulation of the guide vane outlet, the hydraulic loss of the outlet channel is greater than the rear-mounted scheme. The bulb plays a rectifying function when the bulb is placed behind, which greatly eliminates the annular volume of the guide vane outlet, and the water outlet channel has a smaller hydraulic loss. In the front-mounted scheme, the water flow inside the outlet channel squeezes to the outer wall, causing higher entropy production near the outer wall area. The entropy production of the rear-mounted scheme is mainly in the bulb section and the bulb support. This research can provide reference for the design and form selection of a submersible tubular pump device, which has great engineering significance.

Multi-Objective and Multi-Point Aerodynamic Optimization of Transonic Fan Blades

2014 ◽  
Author(s):  
Maryam Khelghatibana ◽  
Jean-Yves Trépanier ◽  
Christophe Tribes ◽  
Jason Nichols
Keyword(s):  
High Speed ◽  
Stokes Equations ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Optimized Design ◽  
Aerodynamic Optimization ◽  
Stall Margin ◽  
Choked Flow ◽  
Multi Objective ◽  
Transonic Fan

A multi-objective and multi-point optimization methodology is developed for aerodynamic design of transonic fan blades. The optimization method aims to increase design efficiency, near stall efficiency and stall margin while maintaining the required design pressure ratio and high speed choke margin. Numerical analyses are performed by solving three-dimensional Reynolds-Averaged Navier-Stokes equations combined with shear stress turbulence model. A multi-level blade parameterization is employed to modify the blade geometry. The proposed method is applied to redesign NASA rotor 67. First, an optimization case with considering two operating conditions at peak efficiency and near stall is performed to demonstrate the relation between near stall efficiency and stall margin. An investigation on Pareto optimal solutions of this optimization shows that the stall margin is increased with improving near stall efficiency. Then, in order to maintain the required choke margin, an operating point at high speed choked flow is added to the optimization process. A final optimized design is selected by considering the interaction of design requirements at all three operating points. The new design presents higher efficiency and stall margin without any reduction in the chocking mass flow rate.

scholarly journals Performance Optimization of Ejector using Computation Fluid Dynamics

2020 ◽  
Vol 8 (5) ◽  
pp. 2905-2910
Keyword(s):  
Fluid Dynamics ◽  
Performance Optimization ◽  
Cfd Simulation ◽  
Experimental Testing ◽  
High Reliability ◽  
Fluid Velocity ◽  
Pressure Ratio ◽  
Operating Cost ◽  
Flow Characteristics ◽  
Operating Conditions

Ejector is a device used for carry low pressure fluids with no mechanical force, high pressure flow. This contains the main nozzle, chamber for suction, chamber for mixing and diffu ser.It is used in vaccum pumps, condensers, steam refrigeration, Because of its simple structure, gas mixing, pneumatic transport (no moving parts) and reliable operation. It is also used in pumps for lifting slurries and waste material containing solids from tanks and sumps. Due to their simplicity and high reliability, however, jet ejectors are widely used in industries with low efficie ncy. The project's goal is to optimize the efficiency of jet ejectors for each operating condition.Consequently, the primary fluid consumption and operating cost is minimized. A commercial computational fluid dynamics tool would be used to analyse the flow characteristics inside the ejector geometry. The results of the CFD simulation could be used to understand the effect of fluid velocity and pressure ratio on the ejector performance. The analysis would also be carried out by varying the primary and secondary nozzle dimensions. Performance of ejectors under various operating conditions is generally obtained through an experimental testing of prototype or scaled ejectors. The availability of performance parameters for such ejectors is limited, and experimental testing can be cost prohibitive.

Simulation of Mechanical Hydraulic System Dynamics Using Coupled Specialized Fluid Models and Multibody Dynamics

2015 ◽  
Author(s):  
Bradford Lynch
Keyword(s):  
Multibody Dynamics ◽  
Cfd Simulation ◽  
Experimental Testing ◽  
Operating Conditions ◽  
Injection System ◽  
Fluid Models ◽  
Hydraulic Systems ◽  
Fuel Injector ◽  
Advanced Technique ◽  
Prime Concern

Durability is a prime concern in the design of hydraulic systems and fuel injectors [1–3] thus an accurate prediction of impact velocities between components and the flow through them is essential to assessing concepts. Simulation of these systems is difficult because the geometries are complex, some volumes go to zero as the components move, and the flow at a single operating condition generally spans Reynolds numbers less than 1 to more than 104[4–8]. As a result of these challenges, experimental testing of prototypes is the dominant method for comparing concepts. This approach can be effective but is far more costly, time consuming, and less flexible than the ability to run simulations of concepts early in the design cycle. A validated model of a fuel injector built from publicly available data [1] is used to present a new approach to modelling hydraulic systems which overcomes many of these obstacles. This is accomplished by integrating several commercially available tools to solve the physics specific to each area within the fuel injector. First, the fuel injector is simulated using a 3D CFD simulation integrated with a 1D CFD system model. The flow in various regions of the injector is then analyzed to determine if the fluid models in these areas can be simplified based on the flow regime. Based on this analysis, a combination of models is assembled to improve the quality of the simulation while decreasing the time required to run the model. The fuel injector is simulated using a multibody dynamics model coupled to a reluctance network model of the solenoid and several fluid models. The first is a 3D CFD simulation which uses novel mesh refinement techniques during runtime to ensure high mesh quality throughout the motion of components, to resolve the velocity profile of laminar flows, and to satisfy the requirements of the RNG k-ε turbulence model and wall functions. This approach frees the analyst from defining the mesh before runtime and instead allows the mesh to adapt based on the flow conditions in the simulation. Due to the highly efficient meshing algorithm employed, it is possible to re-mesh at each timestep thus ensuring a high quality structured mesh throughout the simulation duration. Then a 3D FEM solution to the Reynolds Equation and a statistical contact model is employed to solve for the squeeze films between components and to allow separation and contact between bodies in the control valve. These detailed simulations are integrated with a 1D flow model of the fuel injection system. The results from the detailed coupled simulations are compared to the results from simpler 1D models and measured data to illustrate under which operating conditions a more advanced technique incorporating 3D CFD is worth the additional computational expense versus a traditional 1D model.

Numerical Techniques Applied to Hydraulic Turbines: A Perspective Review

2016 ◽  
Vol 68 (1) ◽  
Author(s):  
Chirag Trivedi ◽  
Michel J. Cervantes ◽  
Ole Gunnar Dahlhaug
Keyword(s):  
Steady State ◽  
Numerical Models ◽  
Guide Vane ◽  
Numerical Technique ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Numerical Techniques ◽  
Transient Conditions ◽  
Hydraulic Turbines

Applications of computational fluid dynamic (CFD) techniques to hydropower have increased rapidly in the last three decades. The majority of the experimental investigations of hydraulic turbines were supported by numerical studies and this has become a standard practice. In the paper, applied numerical techniques and flow modeling approaches to simulate the hydraulic turbines are discussed. Both steady-state and transient operating conditions of the turbines are considered for the review. The steady-state conditions include the best efficiency point (BEP), high load (HL), and part load (PL). The transient conditions include load variation, startup, shutdown, and total load rejection. The performance of the applied numerical models and turbulence modeling with respect to the operating conditions are discussed. The recently developed numerical technique (transient blade row modeling) using the Fourier transformation (FT) method is discussed. This technique allows guide vane and blade passages to be modeled with the pitch ratio other than unity. Numerical modeling and simulation of hydraulic turbines during the transient operating conditions is one of the most challenging tasks because guide vanes' angular movement is time-dependent and mesh should be dynamic/moving. Different approaches applied to simulate the transient conditions and their limitations are discussed. Overall, this review summarizes the role of numerical techniques, advantages, limitations, and upcoming challenges within hydropower.

Flow Evolution in a One and a Half Axial Steam Turbine Stage Under Different Operating Conditions

2015 ◽  
Author(s):  
Berardo Paradiso ◽  
Alessandro Mora ◽  
Vincenzo Dossena ◽  
Giacomo Gatti ◽  
Andrea Nesti ◽  
...  
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
Mass Flow ◽  
Rotational Speed ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Operating Conditions ◽  
Design Stage ◽  
Inlet Guide Vane ◽  
Turbine Stage

In order to investigate in detail the performance of steam turbine stages the Low Speed Test Rig at Politecnico di Milano has been adapted. The setup consists of a one and an half turbine stage with an inlet guide vane. Two kind of experimental approaches are planned in the project: the first, denominated “performance”, has been carried out by the OGTL department of GE Oil&Gas Florence while, at the same time, Politecnico di Milano performed detailed inter-stage measurements with steady probes and time resolved high response pressure probes. An axial steam turbine stage was tested under several operating conditions in terms of rotational speed, mass flow and inlet angle with the aim to provide the functional curves of the machine together with detailed flow-field measurements. In this paper, a detailed description of the inter-stage flow-field is presented for the most relevant operating condition. Then, a comparison between three different points at the same rotational speed (but different mass flow) is proposed. Finally, the effects of different axial gaps on the overall performance of the stage are discussed. In particular, two different vane-rotor axial gaps have been tested by traversing pressure and temperature probes in three different axial planes. The first measurement plane is located at the first stator exit with the aim to provide details of the inlet swirl angle and 3D flow-field generated by the IGV. In the second plane, located at the rotor exit, the effect of different load conditions on the rotor performance and average flow-field is discussed. Finally, the measurements obtained in the third plane, placed at the second stator exit, are afterwards compared with the one obtained in the first plane, in order to evidence the influence of an unsteady inlet flow-field on the stator behaviour. The aim of the work is to provide very detailed aerodynamic measurements; this large amount of data will be used to validate the results of the CFD simulation carried out in the design stage. In this paper the preliminary findings of the steady flow-field will be presented as the basis for further analysis.

scholarly journals Improving Blowout Performance of the Conical Swirler Combustor by Employing Two Parts of Fuel at Low Operating Condition

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1681
Author(s):  
Yixiang Yuan ◽  
Qinghua Zeng ◽  
Jun Yao ◽  
Yongjun Zhang ◽  
Mengmeng Zhao ◽  
...  
Keyword(s):  
Distribution Ratio ◽  
Performance Enhancement ◽  
Experimental Testing ◽  
Stability Boundary ◽  
Operating Conditions ◽  
Nox Emission ◽  
Combustion Stability ◽  
Gas Temperature ◽  
Contact Ratio ◽  
Fuel Distribution

Aiming at the problem of the narrow combustion stability boundary, a conical swirler was designed and constructed based on the concept of fuel distribution. The blowout performance was studied at specified low operating conditions by a combination of experimental testing and numerical simulations. Research results indicate that the technique of the fuel distribution can enhance the combustion stability and widen the boundary of flameout within the range of testing conditions. The increase of the fuel distribution ratio improves the combustion stability but leads to an increase in NOx emission simultaneously. The simulation results show the increase of the fuel distribution ratio causes contact ratio increase in the area of lower reference velocity and gas temperature increase. The increased contact ratio and temperature contribute to the blowout performance enhancement, which is identical to the analysis result of the Damkohler number. The reported work in this paper has potential application value for the development of an industrial burner and combustor with high stability and low NOx emission, especially when the combustion system is required to be stable and efficient at low working conditions.

CFD Simulation of a Co-rotating Twin-screw Extruder: Validation of a Rheological Model for a Starch-Based Dough for Snack Food

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Giorgia Tagliavini ◽  
Federico Solari ◽  
Roberto Montanari
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Second Phase ◽  
Snack Food ◽  
Suitable Model ◽  
Twin Screw Extruder ◽  
Parallel Plates ◽  
Screw Extruder ◽  
Twin Screw

AbstractThe extrusion of starch-based products has been a matter of interest, especially for the pasta and the snack food production. In recent years, twin-screw extruders for snack food have been studied from both structural and fluid dynamics viewpoints. This project started from the rheological characterization of a starch-based dough (corn 34 wt%, tapioca 32 wt%), comparing viscosity values acquired in laboratory with different theoretical models found in literature. A computational fluid dynamic (CFD) simulation recreating the simple case of a fluid flow between two parallel plates was carried out to validate the former comparison. After the rheological validation was completed, the second phase of this work covered a 3D CFD simulation of the first part of the twin-screw extruder (feeding zone). The objective was to find a suitable model for describing the dough rheological behavior and the operating conditions of a co-rotating intermeshing twin-screw extruder. Once the model would be defined, it would allow to investigate several working conditions and different screws geometries of the machine, predicting the evolution of the product rheological properties.

Experimental testing of open pit dump trucks in operating conditions

2020 ◽  
pp. 530-542
Author(s):  
A. G. Zhuravlev ◽  
M. V. Isakov
Keyword(s):  
Power Plants ◽  
Experimental Testing ◽  
Operating Conditions ◽  
Open Pit ◽  
Dump Truck ◽  
Experimental Measurements ◽  
Complex Data ◽  
Special Unit ◽  
Operating Modes ◽  
Dump Trucks

The high importance of optimizing the operation of quarry transport is confirmed by the leading share of its costs in the total cost of mining. The current direction of optimization is the development and implementation of digital technologies for processing complex data on the parameters of transport vehicles. The solution of the above issues should be based on the results of scientific research on the collection and processing of information. Developed a set of techniques to perform experimental measurements of working parameters of mining dump trucks as part of a special unit experiments, and long monitoring measurements. A set of equipment for performing experimental measurements, as well as its installation on a dump truck is presented. The data of experimental measurements and a methodical approach to their analysis are presented. In particular, it shows the identification of operating modes of the power plant and the construction of the load diagram, the identification of elements of the transport cycle, etc. The approach to substantiation of innovative designs of power plants adapted to the conditions of a particular quarry is shown on the example of calculated schedules of energy consumption and reserve of recovery of braking energy. The proposed hardware-methodical complex is a research model for the development of methods for automated data collection and processing in the formation of elements of digital mining production.

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